(a) Field
One or more aspects of example embodiments of the present invention relate to a rechargeable battery module.
(b) Description of the Related Art
A rechargeable battery may be repeatedly charged and discharged, unlike a primary battery that is typically not recharged. Rechargeable batteries having a small capacity may be utilized for portable small electronic devices such as mobile phones, laptop computers, camcorders, etc., and rechargeable batteries having a large capacity may be utilized, for example, for a motor driving power source of hybrid vehicles or electric vehicles.
Rechargeable batteries may utilize a single cell such as for small electronic device applications. Additionally, some rechargeable batteries may utilize a module in which a plurality of cells are electrically connected to each other. Some rechargeable batteries may utilize a pack of battery modules, in which a plurality of modules are electrically connected such as that for driving a motor.
For example, a rechargeable battery module may be formed by arranging a plurality of unit cells in one direction (an x-axis direction), arranging end plates at opposite ends in an arrangement direction of the unit cells, arranging side plates at opposite lateral sides in the arrangement direction of the unit cells, welding (or connecting) the side plates to the end plates, and connecting the unit cells using a bus bar.
The bus bar may be connected to electrode terminals of the unit cells and to a power cable. Accordingly, a current of the unit cells may be discharged through the bus bar to the power cable or charged through the bus bar connected to an external power source by the power cable.
A connection of the bus bar connected to the power cable may be melted by high heat generated by a current concentration phenomenon that may occur in the connection. Therefore, the rechargeable battery module may be unstable in a high-capacity electric vehicle.
Further, in instances in which the rechargeable battery module is mounted in the electric vehicle, the unit cells may experience vibration in an x-axis arrangement direction and a z-axis height direction. Accordingly, the bus bar may experience the vibration of each unit cell in each x-axis direction and in each z-axis direction. As a result, the bus bar may have a weakness in a connecting structure of the unit cells.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does constitute prior art.